The present invention relates to an anti-skid control system for use in motor vehicles which prevents locking of each of wheels of the motor vehicle on vehicle braking operation.
Generally, for execution of anti-skid control, anti-skid control systems are arranged to obtain the maximum wheel speed out of the wheels of a motor vehicle so as to calculate an estimated vehicle speed or slip reference value on the basis of the obtained maximum wheel speed. One problem faced in such a braking system relates to deterioration of the braking efficiency on turning of the motor vehicle. That is, during the turning of the motor vehicle, the speed of the outer side rear wheel generally becomes the maximum wheel speed, and therefore the estimated vehicle speed or slip reference value is calculated on the basis of the wheel speed of the outer side rear wheel. As a result, the inner side wheel is controlled in accordance with a value equal to the value to be used for the outer side wheel, whereby the control start timing for the inner side wheel develops a tendency to advance and the control slip ratio becomes smaller. This causes deterioration of the braking efficiency.